The county clerk is the keeper of most civil and criminal trial court records, naturalizations, copies of marriage records (1908–ca. 1935), censuses (county copies of the federal census and the state censuses), as well as deeds and mortgages. Estate matters are recorded with the clerk of the county Surrogate’s Court (see New York Probate Records), but before 1847 cases involving property of minor heirs and incompetents were often heard in the Court of Chancery. The Inventory of the County Archives of New York State, taken by the Historical Records Survey, 6 vols. (Albany and New York: WPA, 1937–40) was published only for Albany, Bronx, Broome, Cattaraugus, Chautauqua, Chemung, Kings, Richmond, and Ulster counties. Unpublished survey forms are at the New York State Archives, excluding those for the five counties of New York City, which are in that city’s Municipal Archives (see New York Archives, Libraries, and Societies).

Much state court record material is at the state archives and the Old Records Division of the New York County Clerk’s Office. An excellent guide to some of these records is James D. Folts and others, “Duely & Constantly Kept:” A History of the New York Supreme Court, 1691–1847 and An Inventory of Its Records (Albany, Utica, and Geneva Offices), 1797–1847 (Albany, N.Y.: New York State Court of Appeals and the New York State Archives and Records Administration, 1991). Federal court records are at the National Archives—Northeast Region, covering the U.S. district and circuit courts in New York for various periods from 1789 to 1967 and early admiralty courts from 1685 to 1838.